The U.S. Army Corps of Engineers has tapped the South Carolina company for a major rebuild of Puerto Rico's grid. But a wave of microgrid, storage and solar projects are quickly being installed to return power to small parts of the grid.

Regulators trimmed the utility's initial proposal, but it includes $45 million in electric vehicle infrastructure investments and $55 million for energy storage projects on Martha’s Vineyard and Cape Cod.

Concerns over climate change have given rise to a "national keep-it-in-the-ground movement resisting any natural gas project as a matter of principle," Chatterjee said in a speech before gas executives Thursday.

The closely-watched decision could have implications for other utilities — including Pacific Gas & Electric which is under scrutiny for its role in wildfires that devastated Sonoma and Napa counties this fall.

Following October wildfires that devastated Sonoma and Napa counties, California lawmakers are considering a measure to block utilities from recovering costs if their equipment is determined to be at fault.